mikro mk2: rework USB xfers to use libUSB
mikro mk2: rework USB xfers to use libUSB

This open the libUSB backend to maschine, removing the requirement
on the /dev/hidraw interface. Currently the bytes are only read,
and they are not decoded properly, due to an offset difference between
the HidRaw buffer (including endpoint as first byte) and libUSB data
(without said first byte).

Signed-off-by: Harry van Haaren <6e1296516ee88185cd60d9725251227ece1af74d@gmail.com>

openAVproductions/openAV-Ctlra